Impact Powered Devices

ABSTRACT

A device including: a housing; a powered element disposed on or in the housing; and an impact power producing element housed on or in the housing and operatively connected to the powered element, the impact power producing element producing power upon an impact of at least a portion of the housing with another surface; wherein the impact power producing element comprises a mass and one or more spring elements connected at a first end to the mass and at a second end directly or indirectly to the housing and the impact power producing element further comprises one or more magnet elements and a coil, wherein the impact causes a relative motion between the one or more magnet elements and the coil.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional Application of U.S. application Ser.No. 11/447,788 filed on Jun. 6, 2006, now U.S. Pat. No. 7,___,___, theentire contents of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to devices powered by energygenerated by impacts and, more particularly, to consumer devices, suchas a flashlight powered by an impact.

2. Prior Art

In general, all chemical batteries contain hazardous and/or corrosivechemicals, have a relatively short shelf life, are relatively expensiveand introduce waste disposal problems, with the latter beingparticularly the case for lithium based batteries and most rechargeablebatteries. To satisfy the need for alternative power source solutionsfor various devices in general and for flashlights in particular,products have been developed that utilize coil and magnets to generateelectrical energy. Bicycle dynamo and cranking type of dynamos have longbeen used to generate electrical energy. Similar coil and magnetgenerators have also been used in flashlights in the form of rotarycrank type and sliding shaking type generators. The crank typegenerators are relatively heavy and bulky and when designed to be smallas is needed for flashlights, they are cumbersome and tiring to crank.The shake type linear motion generators generate very small amounts ofelectrical energy during each shaking cycle, and are also relativelyheavy. Each of such cranking and shaking devices are limited by thephysical ability of the person providing the energy to crank or shakethe device. In addition, the availability of low cost LED (LightEmitting Diode) lights that consume significantly less electrical energythan conventional light bulbs have made flashlights that harvest energyfrom the environment, including the user induced actions, much morepractical. This is particularly the case for flashlights that are to beused in emergency situations and/or for use in locations whereelectricity is not available such as in the beach, during hiking, andthe like, where flashlights with rechargeable batteries are notpractical.

The only source of energy that is available to humans that could beharvested is mechanical energy. The energy to be harvested by any energyharvesting power source is mechanical in nature. The difference betweenany such energy harvesting power sources is: 1) in the method oftransferring mechanical energy to the energy harvesting device; and 2)in the method of transforming mechanical energy to electrical energy.

A superior method of transferring mechanical energy to the energyharvesting device is ergonomic and does not put undue stress on the userlimbs and joints. The method must also be efficient in making availablethe work done by the human subject to mechanical energy that can beharvested. In addition, the transferred mechanical energy is preferablystored in an intermediate medium to lengthen the period of timeavailable for its conversion to electrical energy since it is generallyeasier and more efficient to convert mechanical energy to electricalenergy and store it in electrical storage devices such as capacitors andrechargeable batteries. The means of transforming mechanical energy toelectrical energy is also desired to produce high enough voltage to makethe process of charging rechargeable batteries and/or capacitors moreefficient.

A need therefore exists for methods and related devices for efficienttransfer of the work done by human muscles to mechanical energy that canbe harvested efficiently and transformed into electrical energy.

SUMMARY OF THE INVENTION

Accordingly, a device is provided. The device comprising: a housing; apowered element disposed on or in the housing; and an impact powerproducing element housed on or in the housing and operatively connectedto the powered element, the impact power producing element producingpower upon an impact of at least a portion of the housing with anothersurface; wherein the impact power producing element comprises a mass andone or more spring elements connected at a first end to the mass and ata second end directly or indirectly to the housing and the impact powerproducing element further comprises one or more magnet elements and acoil, wherein the impact causes a relative motion between the one ormore magnet elements and the coil.

The one or more magnet elements can be at least the mass.

The one or more spring elements can comprise one or more cantileverbeams and the impact power producing element can comprise apiezoelectric element disposed on one or more surfaces of the one ormore cantilever beams.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the apparatus ofthe present invention will become better understood with regard to thefollowing description, appended claims, and accompanying drawings where:

FIG. 1 illustrates a cross sectional schematic view of a firstembodiment of an impact powered flashlight.

FIG. 2 illustrates a variation of the mass-spring unit of the embodimentof FIG. 1.

FIG. 3 illustrates a cross sectional schematic view of a secondembodiment of an impact powered flashlight.

FIG. 4 illustrates a cross sectional schematic view of a thirdembodiment of an impact powered flashlight.

FIG. 5 illustrates a cross sectional schematic view of a fourthembodiment of an impact powered flashlight.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Although the present invention is applicable to numerous types ofdevices, it is particularly useful in the environment of a flashlight.Therefore, without limiting the applicability of the present inventionto a flashlight, it will be described in such environment. Those skilledin the art will appreciate that the methods of the present invention canbe utilized for other devices, such as cell phones, PDA's, cameras,laptop computers and the like. Where the device includes interiorelectronics, such as circuit substrates, which may be prone to breakage,the device can also be designed such that the interior electronics areless prone to breakage from impacts. Designing electronic devices to beimpact resistant, such as from dropping, are well known in the art.

The primary method of mechanical energy transfer to the generatormechanism described herein is an impulsive motion, such as an impactforce. The user is intended to provide the impact (impulsive) force tothe device by hitting it on some relatively hard object, hitting it onsome relatively hard surface, dropping it repeatedly onto somerelatively hard surface, or through other impact inducing actions. Theuser action results in the storage of certain amount of mechanicalenergy in the device in the form of potential energy, or kinetic energy,or their combination. The stored potential energy is then transformedinto electrical energy through the vibration of the system, whichgenerates varying force on at least one piezoelectric element or thelike, which in turn generates varying charges (an AC voltage), which isthen harvested by the system electronics using well known techniques,and used to charge a capacitor and/or rechargeable battery and/ordirectly to provide power, such as to provide light, preferably throughan LED or other low power light source. The induced vibration may beaxial, in bending, in torsion, or their combination.

Referring now to FIG. 1, there is shown a first embodiment of a deviceusing such an impact (or other impulsive motion) to provide power for atleast one powered element associated with the device, in the form of aflashlight shown schematically in FIG. 1. The flashlight 10 has apowered element in the form of a light source 11, which can be one or aplurality of LEDs or other low power light source (collectively referredto as the light source 11). The light source 11 can be mounted in ahousing 12 that contains the energy harvesting electronics and theelectrical energy storage device(s), collectively indicated as element25. Such energy storage devices are well known in the art, such as lowleakage capacitors and/or rechargeable batteries and a detaileddescription thereof will be omitted for the sake of brevity. The impactforce or vibration motion to mechanical energy storage mechanism ispreferably positioned in a handle 13, away from the more sensitiveelectronics 25 and light source 11. The impact force or vibration motionto mechanical energy storage mechanism can comprise an impact powerproducing element, such as at least one mass-spring unit 20, with atleast one relatively rigid mass 14 and at least one transition elements,such as one or more spring elements 15. As discussed below, the impactpower producing element also functions with the application of otherimpulsive motions, such as shaking, either directly or incidental. Thehousing 21 of the handle and preferably the light source housing 12 areconstructed strong enough to resist moderate impact and drops, such aswith plastic. A bottom surface 22 of the flashlight can be constructedof a durable material that can withstand repeated impacts, such as oneor more high-strength plastics. When the user hits the bottom surface 22of the handle housing on a relatively rigid surface, the mass 14 isaccelerated downwards in the direction of arrow 23 during the durationof the impact. Simply, this occurs since once the handle housing isstopped suddenly during a small period of time Δt (usually a fewmilliseconds depending on the physical characteristics of the impactingsurfaces and on how rigid the impacted structure behaves), then the mass14, which is free to accelerate, begins to accelerate and continues toaccelerate during nearly the same period of time Δt. At the completionof this acceleration period, the mass 14 has reached a certain velocityV₀ and has traveled a certain distance D₀. If the effective mass 14 ofthe mass-spring unit 20 is m and the effective spring rate of themass-spring unit 20 is K, then the total mechanical energy E_(m) storedin the mass-spring unit 20 as a result of the aforementioned impact(impulse) force is:

E _(m)=0.5 m V ₀ ²+0.5 k D ₀ ²   (1)

Following the impact, the mass-spring unit 20 will begin to vibrate. Thespring element(s) 15 will then exert a varying force on thepiezoelectric elements 24 positioned on at least one end of the springelements 15, which in turn generate a varying charge with a certainvoltage that is harvested by the harvesting and storage electronics 25and made available to power the light source 11 or other powered elementassociated with the device. As is known in the art, the piezoelectricelements can be made in stacked form, which are widely availablecommercially, for low voltage applications. As shown in FIG. 1, the mass14 can be positioned in between two spring elements 15, each of whichcan exert a varying force on a corresponding piezoelectric element 24positioned at two ends of the handle 13. The piezoelectric elements 24can be electrically connected to the storage electronics 25 or directlyto the light source 11 through appropriate wiring in the housing 12.

The mass 14 can be an integral part of the spring element(s) 15 as shownin FIG. 2. In this configuration, the entire mass-spring unit 20 can beconstructed with a single spring wire helically wound with at least onecompressed coil section 26, which acts as the relatively rigid mass 14of the mass-spring unit 20.

It will be appreciated by those skilled in the art that coil and magnettype of mechanical to electrical energy generators may also be usedinstead of the aforementioned piezoelectric elements with the abovemethod of storing mechanical energy due to impact (impulsive) forces forrelatively slow transformation into electrical energy. The schematics ofone such embodiment is shown in FIG. 3. All elements of this embodimentmay be identical to that of the embodiment shown in FIG. 1 with thedifference that the piezoelectric elements 24 are replaced with the coil27 and magnet 28 elements. The magnet 28 can be the mass 14 of themass-spring unit 20 (and not the coil 27), to eliminate the need toattach wires to the vibrating mass 14. Following the impact or otherimpulsive motion, the magnet 28 vibrates inside the coil, thereforecausing it to generate an AC current, which is then harvested by theharvesting and storage electronics 25.

It is appreciated by those familiar with the art that one or moremass-spring elements can also be mounted perpendicular to the long axisof the flashlight handle to be responsive mostly to an impact or otherimpulsive motion to the side of the flashlight. The schematic of such anembodiment is shown in FIG. 4. The at least one mass-spring unit 40 (inthe schematic of FIG. 4, two of the mass-spring units shown in FIG. 1 or2 are used) is similarly attached to piezoelectric elements 41 toharvest the stored mechanical energy during vibration of the mass-springunit 40 as previously described by the harvesting and storageelectronics 25. The lateral impact can be to the more rigid end 22 ofthe handle 13 in the direction of arrow 43. However, any lateral and/oraxial impact or their combination will accelerate the mass 26 of themass-spring unit 40. It is appreciated by those skilled in the art thatthe mass-spring unit 40 would similarly respond to an axial impact inthe direction of the arrow 42 by vibrating in the axial direction, andthe lateral component of the spring force on the piezoelectric elementwould similarly produce charges that can be harvested by the harvestingand storage electronics 25.

As was previously described, the impact or other impulsive motioninduced vibration may be axial (i.e., in the direction of the length ofthe flashlight), in bending, in torsion, or their combination. When theimpact is essentially in the axial direction 35 and generated by hittingthe bottom surface of the flashlight on a relatively hard surface,bending deflection can be readily induced as shown schematically in FIG.5 by at least one cantilever beam generator assembly 30, consisting of abeam 34 that is attached to the housing 21 of the handle 13 of theflashlight, preferably aided by at least one tip mounted mass 31 (themass can be an integral part of the beam). At least one piezoelectricelement 33 is attached to the surface of the beam 34, preferably closeto its base (the end attached to the flashlight) so that it is subjectedto high tensile strain on one side of the beam 34 and compressive strainon the other side of the beam 34. The varying charge generated due tothe applied compressive and tensile strains on the piezoelectricelements is then supplied to and harvested by the harvesting and storageelectronics 25. It is appreciated by those familiar with the art thatthe piezoelectric elements 33 can be pre-stressed in compression so thatduring the aforementioned vibration they are not subjected to tensilestress since piezoelectric elements can be very brittle and canwithstand only small tensile strains.

It is noted that since the disclosed methods and embodiments rely onvibration of mass-spring units, mechanical energy is transferred to themass-spring units during other flashlight acceleration and decelerationcycles other than those due to impact (impulsive) forces impartedsomewhere on the flashlight body. For example, if the flashlight isplaced inside a car, the vibration of the car will induce vibration ofthe flashlight mass-spring unit and thereby generate electrical energythat is stored, preferably in rechargeable batteries, for later use. Thesame process occurs if a person carries the flashlight in his/her pocketor purse or briefcase, etc., while walking or otherwise moving and wouldhave a charged flashlight for use when needed.

Although the embodiments disclosed herein are discussed as providingelectrical energy upon an impact of the device against a surface, thencan also provide electrical power upon the application of any otherimpulsive motion, such as by shaking, which can be directly applied(such as by a person shaking the device with his or her hand) orincidentally applied (such as due to movement while being stored in acar, pocketbook etc.). However, unlike the shaking apparatus of theprior art, transition elements, such as the spring elements are providedfor storing potential energy, which is in turn converted to electricalpower, such as by the piezoelectric elements or magnet/coilarrangements. A shaking impulsive motion working solely on a movablemass, has limitations as to the frequency by which the mass can vibrate(less than 10 Hz), while the addition of the transition elements, suchas the spring elements, can produce much higher frequencies, such asbetween 10-300 Hz and possibly higher, with the impact impulsive motiongenerally providing the higher frequencies in the range.

While there has been shown and described what is considered to bepreferred embodiments of the invention, it will, of course, beunderstood that various modifications and changes in form or detailcould readily be made without departing from the spirit of theinvention. It is therefore intended that the invention be not limited tothe exact forms described and illustrated, but should be constructed tocover all modifications that may fall within the scope of the appendedclaims.

1. A device comprising: a housing; a powered element disposed on or inthe housing; and an impact power producing element housed on or in thehousing and operatively connected to the powered element, the impactpower producing element producing power upon an impact of at least aportion of the housing with another surface; wherein the impact powerproducing element comprises a mass and one or more spring elementsconnected at a first end to the mass and at a second end directly orindirectly to the housing and the impact power producing element furthercomprises one or more magnet elements and a coil, wherein the impactcauses a relative motion between the one or more magnet elements and thecoil.
 2. The device of claim 1, wherein the one or more magnet elementsis at least the mass.
 3. The device of claim 1, wherein the one or morespring elements comprises one or more cantilever beams and the impactpower producing element comprises a piezoelectric element disposed onone or more surfaces of the one or more cantilever beams.
 4. A devicecomprising: a housing; a powered element disposed on or in the housing;and an impulsive motion producing element housed on or in the housingand operatively connected to the powered element, the impulsive motionproducing element producing power upon an application of an impulsivemotion to the housing; wherein the impulsive motion producing elementcomprises one or more masses operatively connected to one or moretransition elements for storing potential energy from the impulsivemotion; wherein the impulsive motion producing element further comprisesa power producing element operatively connected to the one or moretransition elements for converting the stored potential energy toelectrical energy and the power producing element comprises a magnet andcoil.